Basic Tire Information
How to read tires information:
The first 3 digit number is the “Tire Width” In the case P215, 215 is the overall width of the tire in millimeters.
The 2nd number is the “Aspect Ratio”. Aspect Ratio is the relationship between the tire height and tire width. In this example, 65, represents approximately 65% of the tire width.
R refers to “Radial” - It indicates a radial contstruction of the carcass plies. The carcass plies run in a radius from bead to bead, providing stability, flexibility and ride comfort.
The 3rd number is the “Wheel Diameter” Most SUV and high end cars are 17″ in diameter. In this example, R15 is 15″ diameter tire.
The 4th number is the “Load Index”. The load index can range from 0 to 279 and indicates how much weight the tire is certified to carry at maximum inflation pressure. To check the actual load, you need to refer to the “load index chart”
The 5th number is the “Speed Index”. The speed index indicates the maximum speed at which a tire is certified to carry a load. Speed ratings range from A (lowest) to Z (highest); Q is the lowest rating commonly used for passenger car.